The Men's Nano Puff Vest from Patagonia is a lightweight windproof, insulated gilet that offers excellent protection when the mercury drops. It features durable polyester fabric with a water repellent finish along with Primaloft Gold Eco insulation to help keep you warm and cosy when you need it the most. It has a low profile style that will easily slide into your layering system but will also provide that all important warth as a sleek micro-belay piece. The whole thing stuffs inside the chest pocket so as not to take up too much space when it's in your pack waiting to be used and it's super lightweight so it won't hold you back.